Wearable silicon solar cells

Wearable silicon solar cells may soon become possible... A silicon-based optical fiber with solar-cell capabilities has been developed, scalable to many meters in length. The research may allow for weaving together solar-cell silicon wires to create flexible, curved, or twisted solar fabrics. The findings by an international team of chemists, physicists, and engineers, led by John Badding, a professor of chemistry at Penn State University, build on earlier work addressing the challenge of merging optical fibers with silicon-based chips. Rather than merge a flat chip with a round optical fiber, the team found a way to build a new kind of optical fiber — which is thinner than the width of a human hair — with its own integrated electronic component, bypassing the need to integrate fiber-optics with chips. To do this, they used high-pressure chemistry techniques to deposit semiconducting materials directly, layer by layer, into tiny holes in optical fibers. Now, in their new research, the team members have used the same high-pressure chemistry techniques to make a fiber out of crystalline silicon semiconductor materials that can function as a solar cell — a photovoltaic device that can generate electrical power by converting solar radiation into direct-current electricity. One of the major limitations of portable electronics such as smart phones and iPads is short battery life. Solar-boosted batteries could help solve this problem. “A solar cell is usually made from a glass or plastic substrate onto which hydrogenated amorphous silicon has been grown,” Badding explained. “Such a solar cell is created using an expensive piece of equipment called a PECVD reactor and the end result is something flat with little flexibility.